Translational evidence for lithium-induced brain plasticity and neuroprotection in the treatment of neuropsychiatric disorders

Lithium-discontinuation-induced treatment refractoriness revisited

BACKGROUND

Lithium is effective in the long-term treatment of bipolar disorder. Concerns have been raised about non-responsiveness after discontinuation and resuming previously effective lithium prophylaxis. We reviewed the available literature on this so-called lithium-discontinuation-induced treatment refractoriness (LDITR).

RESULTS

We found 11 case reports and six cohort studies including 403 patients addressing LDITR, and one nation-wide register study providing some additional data on LDITR. Pooling all cohort studies, the percentages of non-responders during re-treatment with lithium ranged from 3.6 to 27.7%, with an average of 17.3%. Non-responsiveness was associated with longer duration of lithium treatment before discontinuation, longer duration of bipolar disorder before start of lithium, faster tapering off lithium, and longer duration of discontinuation.

CONCLUSIONS

There may be a subgroup in whom lithium discontinuation-induced treatment refractoriness exists. However, the vast majority of people respond when lithium is restarted. Moreover, it may be necessary to continue lithium beyond the first relapses to restore long-term prophylactic efficacy.

New Advances in the Pharmacology and Toxicology of Lithium: A Neurobiologically Oriented Overview

Over the last six decades, lithium has been considered the gold standard treatment for the long-term management of bipolar disorder due to its efficacy in preventing both manic and depressive episodes as well as suicidal behaviors. Nevertheless, despite numerous observed effects on various cellular pathways and biologic systems, the precise mechanism through which lithium stabilizes mood remains elusive. Furthermore, there is recent support for the therapeutic potential of lithium in other brain diseases. This review offers a comprehensive examination of contemporary understanding and predominant theories concerning the diverse mechanisms underlying lithium's effects. These findings are based on investigations utilizing cellular and animal models of neurodegenerative and psychiatric disorders. Recent studies have provided additional support for the significance of glycogen synthase kinase-3 (GSK3) inhibition as a crucial mechanism. Furthermore, research has shed more light on the interconnections between GSK3-mediated neuroprotective, antioxidant, and neuroplasticity processes. Moreover, recent advancements in animal and human models have provided valuable insights into how lithium-induced modifications at the homeostatic synaptic plasticity level may play a pivotal role in its clinical effectiveness. We focused on findings from translational studies suggesting that lithium may interface with microRNA expression. Finally, we are exploring the repurposing potential of lithium beyond bipolar disorder. These recent findings on the therapeutic mechanisms of lithium have provided important clues toward developing predictive models of response to lithium treatment and identifying new biologic targets. SIGNIFICANCE STATEMENT: Lithium is the drug of choice for the treatment of bipolar disorder, but its mechanism of action in stabilizing mood remains elusive. This review presents the latest evidence on lithium's various mechanisms of action. Recent evidence has strengthened glycogen synthase kinase-3 (GSK3) inhibition, changes at the level of homeostatic synaptic plasticity, and regulation of microRNA expression as key mechanisms, providing an intriguing perspective that may help bridge the mechanistic gap between molecular functions and its clinical efficacy as a mood stabilizer.

Magnesium-lithium thin films for neurological applications-An in vitro investigation of glial cytocompatibility and neuroinflammatory response

Lithium (Li), a widely used drug for bipolar disorder management, is associated with many side effects due to systemic exposure. The localized delivery of lithium through implants could be an approach to overcome this challenge, for which biodegradable magnesium (Mg)-based materials are a promising choice. In this study, we focus on Mg-Li thin film alloys as potential Li-releasing implants. Therefore, we investigated the in vitro short-term corrosion behavior and cytocompatibility of two alloys, Mg-1.6wt%Li and Mg-9.5wt%Li. As glial cells are the key players of foreign body responses to implants, we used human glial cell lines for cytocompatibility studies, and a murine brain slice model for a more holistic view at the neuroinflammatory response. We found that Mg-1.6wt%Li corrodes approximately six times slower than Mg-9.5wt%Li. Microscopic analysis showed that the material surface (Mg-1.6wt%Li) is suitable for cell adhesion. The cytocompatibility test with Mg-1.6wt%Li and Mg-9.5wt%Li alloy extracts revealed that both cell types proliferated well up to 10 mM Mg concentration, irrespective of the Li concentration. In the murine brain slice model, Mg-1.6wt%Li and Mg-9.5wt%Li alloy extracts did not provoke a significant upregulation of glial inflammatory/ reactivity markers (IL-1β, IL-6, FN1, TNC) after 24 h of exposure. Furthermore, the gene expression of IL-1β (up to 3-fold) and IL-6 (up to 16-fold) were significantly downregulated after 96 h, and IL-6 downregulation showed a Li concentration dependency. Together, these results indicate the acute cytocompatibility of two Mg-Li thin film alloys and provide basis for future studies to explore promising applications of the material. STATEMENT OF SIGNIFICANCE: We propose the idea of lithium delivery to the brain via biodegradable implants to reduce systemic side effects of lithium for bipolar disorder therapy and other neurological applications. This is the first in vitro study investigating Mg-xLi thin film degradation under physiological conditions and its influence on cellular responses such as proliferation, viability, morphology and inflammation. Utilizing human brain-derived cell lines, we showed that the material surface of such a thin film alloy is suitable for normal cell attachment. Using murine brain slices, which comprise a multicellular network, we demonstrated that the material extracts did not elicit a pro-inflammatory response. These results substantiate that degradable Mg-Li materials are biocompatible and support the further investigation of their potential as neurological implants.

Lithium and disease modification: A systematic review and meta-analysis in Alzheimer's and Parkinson's disease

The role of lithium as a possible therapeutic strategy for neurodegenerative diseases has generated scientific interest. We systematically reviewed and meta-analyzed pre-clinical and clinical studies that evidenced the neuroprotective effects of lithium in Alzheimer's (AD) and Parkinson's disease (PD). We followed the PRISMA guidelines and performed the systematic literature search using PubMed, EMBASE, Web of Science, and Cochrane Library. A total of 32 articles were identified. Twenty-nine studies were performed in animal models and 3 studies were performed on human samples of AD. A total of 17 preclinical studies were included in the meta-analysis. Our analysis showed that lithium treatment has neuroprotective effects in diseases. Lithium treatment reduced amyloid-β and tau levels and significantly improved cognitive behavior in animal models of AD. Lithium increased the tyrosine hydroxylase levels and improved motor behavior in the PD model. Despite fewer clinical studies on these aspects, we evidenced the positive effects of lithium in AD patients. This study lends further support to the idea of lithium's therapeutic potential in neurodegenerative diseases.

Accumulation and neuroprotective effects of lithium on hepatocellular carcinoma mice model

AIM

The peripheral tumor growth is accompanied by the accumulation of inflammatory mediators in the blood that can negatively influence blood-brain barrier function and neuronal structure and develop the cancer-associated depression. The aim of the study was to evaluate the neurobiological effects of lithium on hepatocellular carcinoma mice model.

METHODS

In this study we analyzed the locomotor activity of lithium-treated tumor-bearing mice using the Phenomaster instrument. Inductively coupled plasma mass-spectral analysis was used to determine lithium levels in blood, brain, liver, kidneys, tumors and muscle tissues. The prefrontal cortex neurons ultrastructure was assessed by transmission electron microscopy. Expression of BDNF, GRP78, EEA1, LAMP1, and LC3 beta in neurons was determined by immunohistochemical analysis.

RESULTS

A decrease in locomotor activity was found in animals with tumors. At the same time, the low expression levels of the neurotrophic factor BDNF and early endosomal marker EEA1 were revealed, as well as the decreased amount of synaptic vesicles and synapses was shown. Signs of endoplasmic reticulum stress and autophagy development in neurons of animals with tumors were noted. Lithium carbonate administration had a corrective effect on animal's behavior and the prefrontal cortex neurons structure.

CONCLUSIONS

In summary, lithium can restore the neuronal homeostasis in tumor-bearing mice.

Exploring the Neuroprotective Effects of Lithium in Ischemic Stroke: A literature review

Ischemic stroke ranks among the foremost clinical causes of mortality and disability, instigating neuronal degeneration, fatalities, and various sequelae. While standard treatments, such as intravenous thrombolysis and endovascular thrombectomy, prove effective, they come with limitations. Hence, there is a compelling need to develop neuroprotective agents capable of improving the functional outcomes of the nervous system. Numerous preclinical studies have demonstrated that lithium can act in multiple molecular pathways, including glycogen synthase kinase 3(GSK-3), the Wnt signaling pathway, the mitogen-activated protein kinase (MAPK)/ extracellular signal-regulated kinase (ERK) signaling pathway, brain-derived neurotrophic factor (BDNF), mammalian target of rapamycin (mTOR), and glutamate receptors. Through these pathways, lithium has been shown to affect inflammation, autophagy, apoptosis, ferroptosis, excitotoxicity, and other pathological processes, thereby improving central nervous system (CNS) damage caused by ischemic stroke. Despite these promising preclinical findings, the number of clinical trials exploring lithium's efficacy remains limited. Additional trials are imperative to thoroughly ascertain the effectiveness and safety of lithium in clinical settings. This review delineates the mechanisms underpinning lithium's neuroprotective capabilities in the context of ischemic stroke. It elucidates the intricate interplay between these mechanisms and sheds light on the involvement of mitochondrial dysfunction and inflammatory markers in the pathophysiology of ischemic stroke. Furthermore, the review offers directions for future research, thereby advancing the understanding of the potential therapeutic utility of lithium and establishing a theoretical foundation for its clinical application.

Facts and myths about the use of lithium for bipolar disorder in routine clinical practice: an expert consensus paper

BACKGROUND

Bipolar disorder is one of the most burdensome severe mental disorders, characterized by high levels of personal and social disability. Patients often need an integrated pharmacological and non-pharmacological approach. Lithium is one of the most effective treatments available not only in psychiatry, but in the whole medicine, and its clinical efficacy is superior to that of other mood stabilizers. However, a declining trend on lithium prescriptions has been observed worldwide in the last 20 years, supporting the notion that lithium is a 'forgotten drug' and highlighting that the majority of patients with bipolar disorder are missing out the best available pharmacological option. Based on such premises, a narrative review has been carried out on the most common "misconceptions" and "stereotypes" associated with lithium treatment; we also provide a list of "good reasons" for using lithium in ordinary clinical practice to overcome those false myths.

MAIN TEXT

A narrative search of the available literature has been performed entering the following keywords: "bipolar disorder", "lithium", "myth", "mythology", "pharmacological treatment", and "misunderstanding". The most common false myths have been critically revised and the following statements have been proposed: (1) Lithium should represent the first choice for the treatment of patients with bipolar disorder; (2) lithium treatment is effective in different patients' groups suffering from bipolar disorder; (3) Drug-drug interaction risk can be easily managed during lithium treatment; (4) The optimal management of lithium treatment includes periodical laboratory tests; (5) Slow-release lithium formulation has advantages compared to immediate release formulation; (6) Lithium treatment has antisuicidal properties; (7) Lithium can be carefully managed during pregnancy.

CONCLUSIONS

In recent years, a discrepancy between evidence-based recommendations and clinical practice in using lithium treatment for patients with bipolar disorder has been highlighted. It is time to disseminate clear and unbiased information on the clinical efficacy, effectiveness, tolerability and easiness to use of lithium treatment in patients with bipolar disorder. It is necessary to reinvigorate the clinical and academic discussion about the efficacy of lithium, to counteract the decreasing prescription trend of one of the most effective drugs available in the whole medicine.

Low-dose lithium adjunct to quetiapine improves cognitive task performance in mice with MK801-induced long-term cognitive impairment: Evidence from a pilot study

BACKGROUND

Low-dose lithium (LD-Li) has been shown to rescue cognitive impairment in mouse models of short-term mild cognitive impairment, dementia, and schizophrenia. However, few studies have characterized the effects of LD-Li, alone or in conjunction with anti-psychotics, in the mouse model of MK801-induced long term cognitive impairment.

METHODS

The present study used in vivo Ca2+ imaging and a battery of cognitive function assessments to investigate the long-term effects of LD-Li on cognition in mice exposed to repeated injections of MK801. Prefrontal Ca2+ activity was visualized to estimate alterations in neural activity in the model mice. Pre-pulse inhibition (PPI), novel object recognition (NOR), Morris water maze (MWM), and fear conditioning (FC) tasks were used to characterize cognitive performance; open field activity (OFA) testing was used to observe psychotic symptoms. Two treatment strategies were tested: LD-Li [250 mg/d human equivalent dose (HED)] adjunct to quetiapine (QTP; 600 mg/d HED); and QTP-monotherapy (mt; 600 mg/d HED).

RESULTS

Compared to the QTP-mt group, the LD-Li + QTP group showed greatly improved cognitive performance on all measures between experimental days 29 and 85. QTP-mt improved behavioral measures compared to untreated controls, but the effects persisted only from day 29 to day 43. These data suggest that LD-Li + QTP is superior to QTP-mt for improving long-term cognitive impairments in the MK801 mouse model.

LIMITATIONS

There is no medical consensus regarding lithium use in patients with schizophrenia.

CONCLUSION

More pre-clinical and clinical studies are needed to further investigate effective treatment strategies for patients with long-term cognitive impairments, such as chronic schizophrenia.

Sulfur-Containing Foldamer-Based Artificial Lithium Channels

Unlike many other biologically relevant ions (Na+ , K+ , Ca2+ , Cl- , etc) and protons, whose cellular concentrations are closely regulated by highly selective channel proteins, Li+ ion is unusual in that its concentration is well tolerated over many orders of magnitude and that no lithium-specific channel proteins have so far been identified. While one naturally evolved primary pathway for Li+ ions to traverse across the cell membrane is through sodium channels by competing with Na+ ions, highly sought-after artificial lithium-transporting channels remain a major challenge to develop. Here we show that sulfur-containing organic nanotubes derived from intramolecularly H-bonded helically folded aromatic foldamers of 3.6 Å in hollow cavity diameter could facilitate highly selective and efficient transmembrane transport of Li+ ions, with high transport selectivity factors of 15.3 and 19.9 over Na+ and K+ ions, respectively.

Regulation of COX-2 expression by selected trace elements and heavy metals: Health implications, and changes in neuronal plasticity. A review

Trace elements or trace metals are essential components of enzymes, proteins, hormones and play a key role in biochemical processes, cell growth and differentiation, as well as in neurotransmission, affecting human physiology. In nature there are also heavy metals that exhibit toxic effects on the human body, including the brain. The importance of trace elements has been established in neurodegenerative disorders, schizophrenia, depression among others. In parallel, an important regulatory element in the above diseases is cyclooxygenase-2 (COX-2), a modulator of the arachidonic acid (AA) pathway, and a cause of neuroinflammation, and glutamate (Glu) dysregulation, affecting calcium (Ca) metabolism in cells. This review presents the effects of major trace elements and heavy metals on COX-2 expression. Calcium (Ca), zinc (Zn), cadmium (Cd), vanadium (V), nickel (Ni), copper (Cu), and iron (Fe) can potentially increase COX-2 expression, inducing neuroinflammation and Glu excitotoxicity; while magnesium (Mg), lithium (Li), and selenium (Se) can potentially decrease COX-2 expression. The associated mechanisms are described in the article.

Lithium engages autophagy for neuroprotection and neuroplasticity: translational evidence for therapy

Here an overview is provided on therapeutic/neuroprotective effects of Lithium (Li⁺) in neurodegenerative and psychiatric disorders focusing on the conspicuous action of Li⁺ through autophagy. The effects on the autophagy machinery remain the key molecular mechanisms to explain the protective effects of Li⁺ for neurodegenerative diseases, offering potential therapeutic strategies for the treatment of neuropsychiatric disorders and emphasizes a crossroad linking autophagy, neurodegenerative disorders, and mood stabilization. Sensitization by psychostimulants points to several mechanisms involved in psychopathology, most also crucial in neurodegenerative disorders. Evidence shows the involvement of autophagy and metabotropic Glutamate receptors-5 (mGluR5) in neurodegeneration due to methamphetamine neurotoxicity as well as in neuroprotection, both in vitro and in vivo models. More recently, Li⁺ was shown to modulate autophagy through its action on mGluR5, thus pointing to an additional way of autophagy engagement by Li⁺ and to a substantial role of mGluR5 in neuroprotection related to neural e neuropsychiatry diseases. We propose Li⁺ engagement of autophagy through the canonical mechanisms of autophagy machinery and through the intermediary of mGluR5.

Highly Selective Transmembrane Transport of Exogenous Lithium Ions through Rationally Designed Supramolecular Channels

Lithium ions have been applied in the clinic in the treatment of psychiatric disorders. In this work, we report artificial supramolecular lithium channels composed of pore-containing small aromatic molecules. By adjusting the lumen size and coordination numbers, we found that one of the supramolecular channels developed shows unprecedented transmembrane transport of exogenous lithium ions with a Li⁺ /Na⁺ selectivity ratio of 23.0, which is in the same level of that of natural Na⁺ channels. Furthermore, four coordination sites inside channels are found to be the basic requirement for ion transport function. Importantly, this artificial lithium channel displays very low transport of physiological Na⁺ , K⁺ , Mg²⁺ , and Ca²⁺ ions. This highly selective Li⁺ channel may become an important tool for studying the physiological role of intracellular lithium ions, especially in the treatment of psychiatric disorders.

Demographic and clinical characteristics of lithium-treated older adults with bipolar disorder

OBJECTIVES

There is limited information on the characteristics of older adults with bipolar disorder (OABD) treated with lithium, along with safety concerns about its use by older adults. The aim of the present study is to describe the demographic and clinical characteristics of OABD receiving lithium therapy, using data from the Global Ageing & Geriatric Experiments in Bipolar Disorder (GAGE-BD).

EXPERIMENTAL PROCEDURES

Cross-sectional analysis of the GAGE-BD dataset to determine differences and similarities between lithium users and non-users. We analysed data from 986 participants aged 50 years or older (mean age 63.5 years; 57.5% females) from 12 study sites. Two subgroups ('Lithium'; 'Non-lithium') were defined according to the current prescription of lithium. We compared several outcomes between these groups, controlling for age, gender, and study site.

RESULTS

OABD treated with lithium had lower scores on depression rating scales and were less likely to be categorised as with moderate or severe depression. There was a lower proportion of lithium users than non-users among those with evidence of rapid cycling and non-bipolar psychiatric diagnoses. Assessment of global cognitive state and functionality indicated better performance among lithium users. The current use of antipsychotics was less frequent among lithium users, who also reported fewer cardiovascular comorbidities than non-users.

CONCLUSION

We found several potentially relevant differences in the clinical profile of OABD treated with lithium compared with those treated with other mood stabilisers. However, the interpretation of the present results must take into account the methodological limitations inherent to the cross-sectional approach and data harmonisation.

Why lithium should be used in patients with bipolar disorder? A scoping review and an expert opinion paper

INTRODUCTION

Lithium treatment is considered the gold standard for the long-term management of bipolar disorder and recurrent unipolar depression. It is also extremely effective in other psychiatric conditions characterized by impulsivity and aggression, and for the prevention of suicidal behaviours.

AREAS COVERED

This paper provides a scoping review and an expert commentary regarding the use of lithium in adult patients. Available information about efficacy, tolerability, dosing, and switching is analyzed, and the strategies that may be most useful in real-world clinical settings are highlighted.

EXPERT OPINION

Lithium is effective on different domains of bipolar disorder, including the long-term prevention of recurrences of affective episodes, management of acute mania as well as in the prophylaxis of all affective episodes. Lithium has been defined a 'forgotten drug,' since its use in routine clinical practice has been declined over the last 20 or 30 years. Reasons for this trend include lack of adequate training on the management of lithium side effects. Considering its efficacy, use of lithium in ordinary clinical practice should be promoted. Several strategies, such as using slow-release formulations, can be easily implemented in order to minimize lithium side effects and improve its tolerability profile.

What is the Role of Lithium in Epilepsy?

Lithium is a well-known FDA-approved treatment for bipolar and mood disorders. Lithium has been an enigmatic drug with multifaceted actions involving various neurotransmitters and intricate cell signalling cascades. Recent studies highlight the neuroprotective and neurotrophic actions of lithium in amyotrophic lateral sclerosis, Alzheimer's disease, intracerebral hemorrhage, and epilepsy. Of note, lithium holds a significant interest in epilepsy, where the past reports expose its non-specific proconvulsant action, followed lately by numerous studies for anti-convulsant action. However, the exact mechanism of action of lithium for any of its effects is still largely unknown. The present review integrates findings from several reports and provides detailed possible mechanisms of how a single molecule exhibits marked pro-epileptogenic as well as anti-convulsant action. This review also provides clarity regarding the safety of lithium therapy in epileptic patients.

Lithium upregulates growth-associated protein-43 (GAP-43) and postsynaptic density-95 (PSD-95) in cultured neurons exposed to oxygen-glucose deprivation and improves electrophysiological outcomes in rats subjected to transient focal cerebral ischemia following a long-term recovery period

OBJECTIVES

Lithium has numerous neuroplastic and neuroprotective effects in patients with stroke. Here, we evaluated whether delayed and short-term lithium treatment reduces brain infarction volume and improves electrophysiological and neurobehavioral outcomes following long-term recovery after cerebral ischemia and the possible contributions of lithium-mediated mechanisms of neuroplasticity.

METHODS

Male Sprague Dawley rats were subjected to right middle cerebral artery occlusion for 90 min, followed by 28 days of recovery. Lithium chloride (1 mEq/kg) or vehicle was administered via intraperitoneal infusion once per day at 24 h after reperfusion onset. Neurobehavioral outcomes and somatosensory evoked potentials (SSEPs) were examined before and 28 days after ischemia-reperfusion. Brain infarction was assessed using Nissl staining. Primary cortical neuron cultures were exposed to oxygen-glucose deprivation (OGD) and treated with 2 or 20 μM lithium for 24 or 48 h; subsequent brain-derived neurotrophic factor (BDNF), growth-associated protein-43 (GAP-43), postsynaptic density-95 (PSD-95), and synaptosomal-associated protein-25 (SNAP-25) levels were analyzed using western blotting.

RESULTS

Compared to controls, lithium significantly reduced infarction volume in the ischemic brain and improved electrophysiological and neurobehavioral outcomes at 28 days post-insult. In cultured cortical neurons, BDNF, GAP-43, and PSD-95 expression were enhanced by 24- and 48-h treatment with lithium after OGD.

CONCLUSION

Lithium upregulates BDNF, GAP-43, and PSD-95, which partly accounts for its improvement of neuroplasticity and provision of long-term neuroprotection in the ischemic brain.Abbreviations: BDNF: brain-derived neurotrophic factor; ECM: extracellular matrix; EDTA: ethylenediaminetetraacetic acid; GAP-43: growth-associated protein-43; GSK-3β: glycogen synthase kinase-3β; HBSS: Hank's balanced salt solution; LCBF: local cortical blood perfusion; LDF: laser-Doppler flowmetry; MCAO: middle cerebral artery occlusion; MMP: matrix metalloproteinase; NMDA: N-methyl-D-aspartate; NMDAR: N-methyl-D-aspartate receptor; OCT: optimal cutting temperature compound; OGD: oxygen-glucose deprivation; PSD-95: postsynaptic density-95; SDS: sodium dodecyl sulfate; SNAP-25: synaptosomal-associated protein-25; SSEP: somatosensory evoked potential.

Association between lithium use and the incidence of dementia and its subtypes: A retrospective cohort study

BACKGROUND

Dementia is the leading cause of death in elderly Western populations. Preventative interventions that could delay dementia onset even modestly would provide a major public health impact. There are no disease-modifying treatments currently available. Lithium has been proposed as a potential treatment. We assessed the association between lithium use and the incidence of dementia and its subtypes.

METHODS AND FINDINGS

We conducted a retrospective cohort study comparing patients treated between January 1, 2005 and December 31, 2019, using data from electronic clinical records of secondary care mental health (MH) services in Cambridgeshire and Peterborough NHS Foundation Trust (CPFT), United Kingdom (catchment area population approximately 0.86 million). Eligible patients were those aged 50 years or over at baseline and who had at least 1 year follow-up, excluding patients with a diagnosis of mild cognitive impairment (MCI) or dementia before, or less than 1 year after, their start date. The intervention was the use of lithium. The main outcomes were dementia and its subtypes, diagnosed and classified according to the International Classification of Diseases-10th Revision (ICD-10). In this cohort, 29,618 patients (of whom 548 were exposed to lithium) were included. Their mean age was 73.9 years. A total of 40.2% were male, 33.3% were married or in a civil partnership, and 71.0% were of white ethnicity. Lithium-exposed patients were more likely to be married, cohabiting or in a civil partnership, to be a current/former smoker, to have used antipsychotics, and to have comorbid depression, mania/bipolar affective disorder (BPAD), hypertension, central vascular disease, diabetes mellitus, or hyperlipidemias. No significant difference between the 2 groups was observed for other characteristics, including age, sex, and alcohol-related disorders. In the exposed cohort, 53 (9.7%) patients were diagnosed with dementia, including 36 (6.8%) with Alzheimer disease (AD) and 13 (2.6%) with vascular dementia (VD). In the unexposed cohort, corresponding numbers were the following: dementia 3,244 (11.2%), AD 2,276 (8.1%), and VD 698 (2.6%). After controlling for sociodemographic factors, smoking status, other medications, other mental comorbidities, and physical comorbidities, lithium use was associated with a lower risk of dementia (hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.40 to 0.78), including AD (HR 0.55, 95% CI 0.37 to 0.82) and VD (HR 0.36, 95% CI 0.19 to 0.69). Lithium appeared protective in short-term (≤1-year exposure) and long-term lithium users (>5-year exposure); a lack of difference for intermediate durations was likely due to lack of power, but there was some evidence for additional benefit with longer exposure durations. The main limitation was the handling of BPAD, the most common reason for lithium prescription but also a risk factor for dementia. This potential confounder would most likely cause an increase in dementia in the exposed group, whereas we found the opposite, and the sensitivity analysis confirmed the primary results. However, the specific nature of the group of patients exposed to lithium means that caution is needed in extending these findings to the general population. Another limitation is that our sample size of patients using lithium was small, reflected in the wide CIs for results relating to some durations of lithium exposure, although again sensitivity analyses remained consistent with our primary findings.

CONCLUSIONS

We observed an association between lithium use and a decreased risk of developing dementia. This lends further support to the idea that lithium may be a disease-modifying treatment for dementia and that this is a promising treatment to take forwards to larger randomised controlled trials (RCTs) for this indication.

Lithium: Current Clinical Guidelines for Nurse Practitioners

Bipolar disorder is a serious neuroprogressive disorder associated with structural and functional brain changes, multiple comorbidities, and heightened risk for suicide. Lithium has been a first-line treatment for bipolar disorder for more than 50 years and recent research suggests that early identification and treatment of bipolar disorder with lithium can alter the progression of the illness. The purpose of the current article is to review evidence for lithium's neurotrophic and neuroprotective actions and clinical guidelines for safe and effective use. [Journal of Psychosocial Nursing and Mental Health Services, 60(1), 6-9.].

Metabolic risk factors of cognitive impairment in young women with major psychiatric disorder

BACKGROUND

Cognitive performance improves clinical outcomes of patients with major psychiatric disorder (MPD), but is impaired by hyperglycemia. Psychotropic agents often induce metabolism syndrome (MetS). The identification of modifiable metabolic risk factors of cognitive impairment may enable targeted improvements of patient care.

OBJECTIVE

To investigate the relationship between MetS and cognitive impairment in young women with MPD, and to explore risk factors.

METHODS

We retrospectively studied women of 18-34 years of age receiving psychotropic medications for first-onset schizophrenia (SCH), bipolar disorder (BP), or major depressive disorder (MDD). Data were obtained at four time points: presentation but before psychotropic medication; 4-8 and 8-12 weeks of psychotropic therapy; and enrollment. MATRICS Consensus Cognitive Battery, (MCCB)-based Global Deficit Scores were used to assess cognitive impairment. Multiple logistic analysis was used to calculate risk factors. Multivariate models were used to investigate factors associated with cognitive impairment.

RESULTS

We evaluated 2,864 participants. Cognitive impairment was observed in 61.94% of study participants, and was most prevalent among patients with BP (69.38%). HbA1c within the 8-12 week-treatment interval was the most significant risk factor and highest in BP. Factors in SCH included pre-treatment waist circumference and elevated triglycerides during the 8-12 weeks treatment interval. Cumulative dosages of antipsychotics, antidepressants, and valproate were associated with cognitive impairment in all MPD subgroups, although lithium demonstrated a protect effect (all P < 0.001).

CONCLUSIONS

Cognitive impairment was associated with elevated HbA1c and cumulative medication dosages. Pre-treatment waist circumference and triglyceride level at 8-12 weeks were risk factors in SCH. Monitoring these indices may inform treatment revisions to improve clinical outcomes.

Immune Signaling Kinases in Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD)

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disorder of motor neurons in adults, with a median survival of 3-5 years after appearance of symptoms, and with no curative treatment currently available. Frontotemporal dementia (FTD) is also an adult-onset neurodegenerative disease, displaying not only clinical overlap with ALS, but also significant similarities at genetic and pathologic levels. Apart from the progressive loss of neurons and the accumulation of protein inclusions in certain cells and tissues, both disorders are characterized by chronic inflammation mediated by activated microglia and astrocytes, with an early and critical impact of neurodegeneration along the disease course. Despite the progress made in the last two decades in our knowledge around these disorders, the underlying molecular mechanisms of such non-cell autonomous neuronal loss still need to be clarified. In particular, immune signaling kinases are currently thought to have a key role in determining the neuroprotective or neurodegenerative nature of the central and peripheral immune states in health and disease. This review provides a comprehensive and updated view of the proposed mechanisms, therapeutic potential, and ongoing clinical trials of immune-related kinases that have been linked to ALS and/or FTD, by covering the more established TBK1, RIPK1/3, RACK I, and EPHA4 kinases, as well as other emerging players in ALS and FTD immune signaling.

Development of a Portable Method for Serum Lithium Measurement Based on Low-Cost Miniaturized Ultrasonic Nebulization Coupled with Atmospheric-Pressure Air-Sustained Discharge

An accurate, rapid but cheap, and portable method for monitoring of serum lithium (Li) is highly desirable for mental patients who take Li medicine for treatment. Conventional techniques are usually bulky, costly, and cannot provide on-site real-time measurements. Herein, a miniaturized, reliable, cost-effective, and portable optical emission method for rapid and sensitive determination of serum Li was developed based on a combination of miniaturized ultrasonic nebulization (MUN) and a low-power (≈22 W) atmospheric-pressure air-sustained discharge (APAD) excitation source. The proposed method eliminates the use of any compressed gas or pump and can achieve serum Li detection within 40 s with low sample consumption (less than 20 μL serum). Except for dilution with water, no extra treatment is needed for serum Li analysis by MUN-APAD-OES. In addition, it offers a significant advantage of good tolerance to the coexisting high concentration of Na, K, Ca, and Mg, which is in contrast with the obvious matrix effect encountered in conventional inductively coupled plasma optical emission spectrometry (ICP-OES). Different operating parameters affecting the performance of MUN-APAD-OES were evaluated. Under optimized conditions, the detection limit of Li (670.8 nm) was calculated to be 0.6 μg L^-1 (6 μg L^-1 in serum). Finally, the accuracy of the proposed method was validated by the analysis of two certified reference materials (Seronorm serum L-1 and L-2 RUO), six real human serum samples, and eight real animal serum samples. All of the results indicate that the low-cost and low-power MUN-APAD-OES provides a promising reliable method for on-site serum Li measurement and may also be extended to other elements.